A BMI of 24 sits comfortably inside the normal band on an American chart. In an Indian endocrinologist's clinic, the same number can be a reason to start looking harder. That is not a difference of opinion between two doctors.

It is a formal divergence between two sets of clinical guidance that now disagree on three things. They disagree on the weight at which risk begins, whether obesity is one category or a staged disease, and how much a clinician measures before deciding anything. For an Indian adult trying to read their own body, the chart being used matters as much as the reading on it.

• Indian guidance treats a BMI of 23 as the point to start screening and 25 as obesity, against the international thresholds of 25 and 30.
• Applying the Indian cutoffs reclassifies an additional slice of the population as overweight or obese overnight, with nothing about their bodies having changed.
• Indian consensus stages obesity by its effect on the body, where WHO and US definitions rest primarily on a single BMI number.
• The divergence is a deliberate response to South Asian body composition data rather than a stricter reading of the same evidence.
• A thorough clinical assessment in India prioritizes multiple parameters like central adiposity and comorbidities instead of relying solely on weight.

The starting point of the disagreement is the number itself. For Asian Indian adults, a 2009 Indian consensus statement set overweight at a BMI of 23.0 to 24.9 and obesity at 25 and above. Abdominal obesity was flagged at a waist of 90 cm in men and 80 cm in women. The authors estimated that adopting these limits would classify an additional 10 to 15 per cent of the Indian population as overweight or obese, purely by moving the line.

International guidance draws that line elsewhere. The World Health Organization defines adult overweight at a BMI of 25 and obesity at 30. US bodies follow the same numbers. The CDC sorts obesity into classes at 30, 35 and 40. US screening guidance recommends screening all adults but reserves intervention for a BMI of 30 and above, with no lower ethnic-specific trigger.

How Indian, WHO and US Obesity Guidelines Differ

Overweight

• Asian-Indian guidance: BMI 23 to 24.9
• WHO and international guidance: BMI 25 or above
• US guidance: BMI 25 to 29.9

Obesity

• Asian-Indian guidance: BMI 25 or above
• WHO and international guidance: BMI 30 or above
• US guidance: BMI 30 or above

Abdominal obesity

• Asian-Indian guidance: Waist circumference of 90 cm or more for men and 80 cm or more for women
• WHO and international guidance: Regional cutoffs are acknowledged
• US guidance: Waist circumference is used, but there is no lower ethnic-specific cutoff

Staging by impact

• Asian-Indian guidance: Obesity is divided into Stage 1 and Stage 2.
• WHO and international guidance: Staging by impact is not part of the core BMI definition.
• US guidance: Staging by impact is not part of the core BMI definition.

Notably, the international bodies are aware of the gap. WHO's 2004 expert consultation on Asian BMI concluded that a substantial share of Asian people carry high diabetes and cardiovascular risk at a BMI below 25. It identified public health action points at 23, 27.5, 32.5 and 37.5. It stopped short of changing the global definition, keeping 25 and 30 as the international categories. India took the action point and built its national guidance around it. The West kept it as a footnote.

The reason Indian guidance lowers the line is that the Indian body stores fat differently, and that difference is measurable rather than cultural. At the same BMI, South Asian adults tend to carry more body fat, more of it visceral, and less muscle than white European reference populations. This is the pattern often described as the thin-fat or thin-outside, fat-inside phenotype. It describes a person who looks lean on the scale while carrying the metabolic load usually associated with a heavier body.

That extra visceral load is what pushes cardiometabolic risk forward to lower weights. Where Western charts treat a normal BMI as reassurance, Indian guidance treats it as a reason to look past the scale. Visceral fat can sit at levels that raise risk while BMI still reads normal. It is the same reason a normal BMI does not guarantee metabolic health in an Indian adult in the way it is often assumed to in a Western one. The 2009 statement grounded its lower thresholds explicitly in this body composition and morbidity data rather than in a general preference for caution.

Expert endocrinologists frequently warn that visceral fat accumulation occurs silently. The direction of this argument is well supported. What remains a matter of consensus rather than trial proof is the precise placement of the line. Whether 23 specifically, versus 22 or 24, is the value that best improves outcomes has not been tested in long-term randomised studies. Indian guidance is candid about this, presenting the threshold as the best available reading of risk data, not as a validated endpoint.

The deeper divergence is structural. WHO and US definitions largely answer one question, is the BMI above the line, and sort by how far above. The CDC's classes are still BMI bands. Indian consensus has moved to a different question entirely. It asks not just how much excess weight exists, but what that weight is doing to the person.

India's 2025 revised definition of obesity in Asian Indians formalises this into two stages:

Stage 1 describes increased adiposity, which is a BMI above 23, without discernible effect on organ function or daily activities.

Stage 2 is the more advanced state. It requires a BMI above 23 plus raised central adiposity, seen as an excess waist circumference or a waist-to-height ratio above 0.5. It also requires either symptoms that limit daily activity, such as breathlessness, joint pain or fatigue, or an established obesity-related condition like type 2 diabetes, high blood pressure or abnormal lipids. The same guidance also uses a plain-language 4M lens for clinical assessment.

This covers the medical, musculoskeletal, mood-related and monetary weight of the condition.

The practical effect is that two Indians with an identical BMI of 27 can receive different diagnoses. Consider a real-world example in a clinic. Patient A has no symptoms, normal blood sugar, and a normal waist size. They may be classified as Stage 1. Patient B carries central fat and early diabetes. They are diagnosed with Stage 2. A US chart would file both in the exact same class. This staging developed through a structured expert Delphi process rather than from outcome trials. Indian guidance is transparent that the framework is built for precision rather than yet validated by long-term data.

The through-line across all of this is that an Indian obesity assessment is designed to be multi-parameter from the start. Rather than reading BMI and stopping, the guidance combines the BMI with a waist measurement and a waist-to-height ratio. It adds a check for the symptoms that mark functional limitation, and a screen for common comorbidities before settling on a stage. Central adiposity is not an optional extra here. For Stage 2, it is a required criterion.

What the published guidance does not lay out in the open literature is the exact first-consult investigation panel a specific endocrinologist runs. It does not dictate which blood tests, which imaging, which endocrine screens, and in what order to perform them. The 2025 update describes comprehensive evaluation and full characterisation of the patient's adiposity. However, it does not reproduce a standardised test-by-test workup, and no single national panel is published for every clinician to follow. That part varies with the individual clinician and the patient in front of them, and it is not something a reader can safely infer from a chart. It is a question for a consultation, not an article.

For an Indian reader, the honest summary is this. The diagnosis you would receive here is built to catch risk that a Western BMI reading would wave through, and it rests on more than one number by design.

If your BMI has always looked fine on an international calculator, the single most useful thing to know is that it may have been the wrong chart. Against Indian thresholds, and once waist and waist-to-height ratio enter the picture, the same body can tell a different story. That story is what determines whether anything needs attention.

None of this is a diagnosis you can give yourself. Staging, and the decision about what it means, is made by a registered clinician after an assessment, not by a calculator or an app. It is always best to book a consultation to have those measurements read by a clinician who is using the chart built for your body. The key takeaway is to always seek professional guidance tailored to your specific ethnic and metabolic profile.

This article is for general information and education only and is not medical advice, diagnosis, or treatment. GLP-1 and other medications referenced are prescription-only and are appropriate only for certain people under the supervision of a qualified clinician. Do not start, stop, or change any medication based on this article. Please consult a registered medical practitioner about your individual circumstances. Information reflects what was available at the time of review and may change.